Bloom syndrome

Bloom syndrome is an autosomal recessive disorder with a higher prevalence among Ashkenazi Jews and the Japanese due to a founder effect. Caused by mutations in the {BLM} gene, a multifunctional ATP-dependent DNA helicase, it leads to genomic instability and defective DNA repair mechanisms, resulting in a significantly increased frequency of sister chromatid exchanges (SCEs). Clinically, individuals with Bloom syndrome exhibit a range of characteristics such as dwarfism, distinctive facial features, skin abnormalities, and immune deficiencies. Moreover, they are at a heightened risk of developing diverse cancers, including leukemias, lymphomas, and carcinomas, at a relatively young age. The syndrome, though rare, presents challenges in prognosis, with many patients succumbing to complications, primarily cancer-related, by their mid-20s. Cytogenetic studies reveal pathognomonic features, including elevated SCE rates and chromosomal breaks, aiding in diagnosis. Despite the challenges posed by this condition, ongoing research endeavors aim to understand its mechanisms and improve management strategies for affected individuals.